Help with super and zune

Hey. I am back with another issue.
Ok, so I ripped a dvd and now I want to use super to convert the VOB files to microsoft zune. It has a selection for that on Super. But whenever I do that. It keeps saying error.
I even first converted the files to an avi which worked fine. Then using those, tried to reconvert to microsoft zune, still says error.
Any idea why? I am using the default in super. I didn't change anything.
thanks